I strongly recommend getting there the Saturday (or Sunday) before the start to watch them put the finishing touches on the large sculptures, watch the three man team competition, and watch them carve the ice sculptures. Then I would stay through Wednesday so you can see the operning ceremonies, all the sculptures lit up at night, and enjoy the nightlife among the ice sculptures. The Sapporo Snow and Ice Festival is an event that everyone should try to attend at least once; it was fantastic!

Marc

PS At a restaurant near the Snow Festival, we were pleased to find that you could order a bottle of whisky, glasses, and ice instead of having to order individual drinks; hadn't experienced that in the US in many years.